The invention relates to an X-ray examination apparatus. The apparatus comprises an X-ray tube provided with an anode pipe. The anode pipe accommodates, at an end thereof remote from the tube, an anode and a radiation window, and an X-ray detection device.
An X-ray examination apparatus of this kind is described in U.S. Pat. No. 4,057,733. The dental apparatus described therein comprises an X-ray source with an anode pipe. The anode pipe can be inserted into the mouth of the patient for the formation of images, so that the X-ray focus and hence the source are intraoral. For X-ray fluoroscopy, the apparatus further comprises an extraoral radiation detection device which is an X-ray image intensifier tube. The X-ray image intensifier tube is arranged so as to be displaceable along the direction of a principal ray of the image forming X-ray beam and rotatable about the X-ray tube.
During the process of scanning a set of teeth by means of such an apparatus, freedom of movement is restricted. Moreover, because the radiation is incident at different angles for different members of a set of teeth, distortion occurs, and a change over of the scanning process from that for the upper set of teeth to that for the lower set of teeth and vice versa is comparatively difficult. Moreover, the introduction of such a range of movement also reduces the degree of reliability with respect to correct image formation.